Borderlands 2 deveoper Gearbox Software is working with Microsoft to solve issues with the game's Compatibility Pack.
The 258MB download is needed to keep all players up to speed with content added in new DLC releases.
A new version of the pack was released this week, alongside the third major Borderlands 2 expansion, Sir Hammerlock's Big Game Hunt.
Some players have reported errors downloading the pack - something Gearbox says should now be fixed.
"We're hearing that the Compatibility Pack is now downloading properly on Xbox 360 for some and are continuing to work with Microsoft on this," a spokesperson wrote on the company's support website.
"For those still experiencing the 'Can't Download Compatibility Pack' error, please try adding the latest Compatibility Pack to your download queue from Xbox.com via this link.
"If that doesn't resolve the issue, please submit a request for additional troubleshooting."
Sir Hammerlock's Big Game Hunt is now available on all platforms.
"You'll laugh, you'll die, you'll blow the teeth out of a wandering Borok the size of a small camper van," Eurogamer's Chris Donlan reported in our Sir Hammerlock's Big Game Hunt DLC review.
"Compared to the heights of Mr Torgue's Campaign of Carnage, with its masterful blend of Kayfabe jokes and sustained bar-fight intensity, Hammerlock can't quite match up. But it provides several great new reasons to return to Pandora, and that's enough to seal the deal."